Health Hazard Evaluation Report, HETA-2000-0291-2840, E.I. DuPont de Nemours and Co., Inc., Richmond, Virginia.
On May 10, 2000, the National Institute for Occupational Safety and Health (NIOSH) received a health hazard evaluation (HHE) request from members of the Ampthill Rayon Workers Inc. (ARWI) employed at the E. I. DuPont de Nemours and Co., Inc., (DuPont) facility in Richmond, Virginia. The request indicated that persons working in the para-aramid (Kevlar) fiber production area were experiencing "infected gland, sore throats, and infections" that they believed may be a result of workplace exposures. In response to the request, NIOSH investigators visited the facility on July 26-28, 2000. Environmental monitoring was conducted to characterize exposures in the Spinning and Finishing (Beaming and Roving) areas. Total dust exposures in the Beaming and Roving areas of the Finishing area were below 0.02 milligrams per cubic meter (mg/m3), the limit of detection for the sampling method used. Fiber exposures in the Roving and Beaming areas were 0.01 and 0.02 fibers per cubic centimeter (f/cc), below the exposure criterion of 0.5 f/cc we used for this evaluation. Sulfuric acid mist exposures in the Kevlar Spinning area during routine activities ranged from less than 0.003 mg/m3 to 0.082 mg/m3. The NIOSH, American Conference of Governmental Industrial Hygienists (ACGIH), and U.S. Department of Labor, Occupational Safety and Health Administration (OSHA) established an exposure limit for sulfuric acid of 1 mg/m3 as a time-weighted average. The local exhaust systems in the Spinning area were examined for air flow and air speed. We identified "dead spots" and relatively slow air velocities across the face of the hoods. NIOSH medical officers interviewed 46 DuPont employees: 25 systematically and 3 voluntarily selected of 50 Spinning area employees, 15 of 16 current Finishing area employees, and 3 former Finishing area workers. Medical records of 12 employees seen for potentially work-related health concerns were reviewed. Fourteen (56%) of the twenty-five systematically selected, current Spinning area employees reported work-related episodes of upper respiratory symptoms, two reported brief work-related episodes of shortness of breath, and four reported symptoms mainly occurring during work with the interlacing part of the machine. Of the 15 interviewed Finishing employees, 4 (27%) reported work-related allergy symptoms and/or increased frequency of upper respiratory infections, including sinusitis, 1 reported the onset of episodes of wheeze, and shortness of breath after beginning work in the area, and 1 current and 2 prior Finishing area employees reported symptom onset or worsening after installation of the interlace boxes. Three of five medical records received for Spinning area workers documented findings of throat irritation and/or chronic hoarseness; two of these medical reports mentioned work-related sulfuric acid mist exposure as a potential cause and one documented a physician-recommended job transfer. No association between symptoms and work environment was reported in medical records of four current Finishing employees. Medical records of three former Finishing area workers revealed two with eye and/or throat irritation who had both been restricted at certain times from the Roving interlace area by the company physician, and one with new-onset asthma diagnosed one year after beginning work in the Finishing area, but with no documentation of a specific cause, including exposures in the workplace. All measured concentrations of dust, fibers, and sulfuric acid in this evaluation were well below available guidelines or standards. The symptoms reported by DuPont employees evaluated in this HHE are non-specific and cannot be directly related to specific exposures in the areas evaluated, however, it is possible that elevated concentrations of workplace contaminants could have occurred in the past and contributed to reported symptoms. Recommendations are provided in this report to address health and safety issues identified during our evaluation.